Latching mechanism for double swing doors



L. N. BREDEMUS May 30, 1967 LATCHING MECHANISM FOR DOUBLE SWING DOORS Filed June 28, 1965 mum-mumm- I NVEN TOR. L E ONARD N. BEE DE MUS ARNEYS United States Patent 3,322,451 LATCI-IING MECHANISM FOR DOUBLE SWING DOORS Leonard N. Bredemus, 80 Hatch Ave., St. Paul, Minn. 55117 Filed June 28, 1965, Ser. No. 467,461 6 Claims. (Cl. 292-137) This invention relates generally to latching apparatus for doors and particularly to improved apparatus for reliably latching doors which can be swung open and closed in either direction.

A double swing door, that is a door-which can swing in either direction, is particularly useful in a variety of applications. For example, where there is a large amount of two-way traflic through an exit or entrance. Of course, the barroom door of the old western frontier days is a classic example. Another and more pressing present day need for this type of door is in institutions where handicapped persons may be unable to or may find it exceedingly difficult to manipulate doors which swing open in only one direction and swing closed only in the other direction. One of the greatest difficulties heretofore encountered where the double swing door has been in use has been the inability of the door to latch reliably when being closed while still capable 'of being swung in either direction.

It is the general object of this invention to provide a latching mechanism for a double latch door.

More particularly it is an object of this invention to provide a positive latching of a double swung door so that the door will latch in the closed condition each time it reaches the closed condition without oscillating back and forth thereby providing a positive stop for the door yet allowing freedom to open in either direction.

A further object of this invention is to provide a latching apparatus for a double swing door which can be locked in the closed condition without requiring an additional bolt.

Still a further object of this invention is to achieve all of the foregoing objects with an apparatus which is neat and not unsightly.

Still a further object of this invention is to achieve all of the foregoing objects with a device which is a relatively inexpensive item of manufacture.

As a feature of this invention, the double swing door will positively latch in the closed condition even in those instances where the door may be warped.

These and other objects and features of this invention will become apparent during the course of the following detailed description with reference to the accompanying drawings in which:

FIGURE 1 is a top sectioned view showing the latching region of a double swing door to illustrate the operation of a preferred embodiment of this invention in a somewhat schematic manner;

FIGS. 2, 3 and 4 are respectively front, side and top views showing construction details of a latch bolt for a double swing door such as used in the embodiment illustrated in FIG. 1;

FIGS. 5 and 6 are respectively front and bottom views showing more detailed construction of a strike plate such as shown as part of the preferred embodiment of this invention in FIG. 1.

A door 10 may be conveniently hinged on the right hand hinge jamb or doorway member, not shown, in a manner to allow the door to swing in both directions in the door frame. In the usual fashion, the door 10 contains a latching mechanism within a recess area 11. The mechanism, which is shown somewhat schematically in FIG. 1, includes a latch bolt 12 which is normally "ice urged by spring 13 to an extended position so that it will seat in a latching hole or recess 14 in the doorway frame when the door 10 is closed, such as is illustrated in FIG. 1. The latching hole 14 is formed in the left hand jamb or doorway frame member 15 and is sufficiently large to receive the extended portion of the bolt 12. Attached to the latching jamb 15 in any convenient manner is a metallic strike plate 16 which contains a strike hole 17 overlying the entrance to the latching hole 14. On either side of the strike hole 17 the strike plate 16 is straight or fiat for a certain distance and then is formed into tapered sections 18 and 19 at the extreme sides. Details of the construction of the strike plate 16 can be observed in FIGS. 5 and 6.

Some of the details of the construction of the latch I bolt 12 can be seen in FIGS. 2-4. The most forward part 20 of the latch bolt 12 is of rectangular box-like construction having straight side walls 21, 22 and a flat face 23. The rear portion 30 of the latch bolt 12 is likewise preferably constructed in a rectangular fashion having straight side walls 24 and 25. Between the forward and rear parts of the latch bolt is a tapered portion 26 having tapered surfaces 27 and 28 which join the two rectangular sections 20 and 30 to one another. Typically, dimensions for the latch bolt as shown in FIGS. 2, 3 and 4 may be as follows: Overall length in the order of 1 /2 inches with the portion normally extending beyond the door as measured from the edge of the door (denoted by dashed line 29 in FIG. 4) in the order of /z-inch; width as observed in FIG. 2 may be in the order of Vs-inch; the height as viewed in FIGS. 2 and 3 may be in the order of one inch; depth of the straight side walls 21 and 22 may be in the order of -inch; and the length of the flat projection of the tapered walls 27 and 28 as viewed in FIG. 3 may be in the order of & inch. Some typical dimensions for the strike plate are as follows: Strike hole width in the order of -inch; the flat portions of the strike plate extending from the sides of the strike hold to the beveled portions 18 and 19 may be in the order of one inch each; and the tapered portions 18 and 19 may have a length in the order of -inch and an angle of taper in the order of 45. It should be understood that these dimensions are only exemplary and not intended to be limitive.

Referring back again to FIG. 1 assume that the door 10 is initially in the arbitrarily designated forward direction as indicated by arrow 31. The latch bolt 12 will be pushed out to its furtherest extended condition by the spring 13 but will be stopped from overextending by any well-known suitable stop mechanism, not shown.

. As the door swings rearward opposite the direction of arrow 31, the leading edge of the front face 23 (where it meets the straight-sided wall 21) of the most forward extended portion 20 of the latch bolt will strike the beveled portion 19 of the strike plate 16, as illustrated by shadow line in FIG. 1. The taper of the bevel is chosen so that the bolt 12 will be forced back into the recess 11 in the door in opposition to the force of spring 13 as the door continues to move in its arc toward the closed condition. As the trailing edge of the front face 23 (where it meets wall 22) passes the forward edge of the strike hole 17 the bolt 12 starts to enter the latching hole 14 through the strike hole 17. As the door continues its movement, the straight side wall 21 will eventually strike the other side of the strike hole 17 which will stop any further backward travel of the door. The force of the spring 13 biases the bolt 12 to its extended condition so that it seats in the latching hole 14. Either or both of the taper surfaces 27 and 28 will at least partially ride against the sides of the strike hole 17 to guide the bolt 12 to its seated condition by centrally locating it with respect to the hole 14 and the strike hole 17 so that the bolt will be firmly and completely seated within the recess. It should be noted that in this condition the straight side walls 24 and 25 will provide a positive latch and will prevent the door from being opened or unlatched until the bolt 12 is withdrawn in the usual manner by a doorknob or the like. It should be observed because of the straight side walls 21 and 22 of the stop portion of the bolt and the substantially narrow width of the face 23 as compared to the width of the strike hole 17, the door will be brought to an immediate stop as soon as the bolt 12 begins to enter into the latching hole 14 through the strike hole 17. It should also be observed that the mechanism will operate in a similar manner regardless of the direction in which the door is swung. The bevel portions 18 and 19 on the strike plate 16 offset the effect of the walls 21 and 22 so that bolt is forced back into the recess 11 in the door until the door reaches its position for latching.

It is possible that due to warping or other reasons, the strike plate hole 17 may not be properly centered with respect to the bolt 12. The mechanism will operate, however, to seat the bolt within the strike hole and at least partially within the latching hole 14 since the tapered walls 27 and 28 will permit the bolt 17 to enter into the latching hole until at least some part of these walls comes in contact with the sides of the strike hole 17. So even though the bolt may not be completely contained within the latching hole 14 to the desired extent, it will be to a sufficient degree to afford a positive latch.

Although the preferred embodiment of the invention has been described herein as being in a general rectangular shape, it is apparent that other configurations, such as cylindrical, can be used with equal effectiveness. All of the normally required additional functions of the latch bolt, principally the capability of being locked closed, can be readily incorporated in the usual manner without requiring an additional lock bolt or locking hole. The simplicity of construction of the bolt, strike plate and latching recesses makes this invention adaptable for use in a relatively inexpensive manner.

It should be noted that the invention described herein also can be used in single swing doors so that the same latching mechanism can be used on all doors in large construction projects thereby providing uniform appearance and likely some saving in costs.

I claim:

1. Latching apparatus for a double swinging door, a combination: a strike plate mounted on a doorway frame having a hole coextensive with a latching recess in the frame, said strike plate having side beveled portions approaching said hole; a latch bolt slidably mounted within the door and normally urged to an extended position away from the door for seating in said latching recess; the extended portion of said bolt consisting of a front end section having sides parallel to the plane of the door defining a bolt-face width which is substantially less than the width of the strike hole, a rearward section having sides parallel to the plane of the door defining a width which is only slightly less than the width of said strike hole and a section intermediate said front and rearward sections having at least one tapered side defining a width that ranges between the other two defined widths.

2. Latching apparatus for a double swinging door, in combination: a strike plate mounted on a doorway frame, said plate consisting of a relatively fiat panel having a centrally located strike hole coextensive with a latching recess in the frame, and beveled panels on either side of the flat panel; a latch bolt slidably mounted within the door and being urged away from the door to an extended condition for seating in said latching recess when the door is closed; the most forward part of the bolt having sides parallel to the plane of the door and being substantially narrower than the strike hole; the most rearward part of the extended portion of the bolt having sides parallel to the plane of the door and being only slightly narrower than the strike hole; and the part of the bolt between said forward and rearward parts having its sides tapered between the corresponding sides of said forward and rearward parts.

3. The apparatus as described in claim 2 wherein the strike plate beveled panels are beveled to a degree such that when the door is swung closed the bolt is forced back into the door during contact with the strike plate until the bolt face is located opposite the strike hole.

4. Latching apparatus for a double swinging door, in combination: a strike plate attached to an inner facing side of a doorway frame, said plate consisting of a rela tively fiat panel having a centrally located strike hole coextensive with a latching recess in the frame and rigidly attached beveled panels at either side of said flat panel; a latch bolt slidably mounted within the door and being yieldably urged away from an edge of the door to an extended position for seating in said latching recess when the door is closed; said bolt consisting of,

(a) a front end stop portion having sides parallel to the plane of the door and being substantially smaller in width than the strike hole whereby when the door is swung closed the stop portion enters at least part way into the strike hole and stops further travel of the door,

(b) a rearward disposed latching portion having sides parallel to the plane of the door and being only slightly narrower smaller than the strike hole whereby when the door is stopped by the stop portion entering the strike hole, the latching portion of the bolt seats in the latching recess, and

(c) a tapered side portion between the stop portion and the latching portion for guiding the advance of the latching portion into seating engagement in the latching recess.

5. Apparatus as in claim 4 wherein the beveled panels of said strike plate contact the stop portion of the bolt to force the bolt back into the door when the door is swung closed.

6. The apparatus as in claim 5 wherein the front end stop portion of the bolt is centrally located with respect to the outer boundaries of the latching portion.

References Cited UNITED STATES PATENTS 16,676 2/1857 Adams 292340 311,787 2/1885 Rockfellow 2922 X 562,515 6/1896 Endres 2922 1,816,259 7/1931 Lande -462 X 2,272,241 2/ 1942 Fendring 292340 MARVIN A. CHAMPION, Primary Examiner.

EDWARD C. ALLEN, Examiner.

J. R. MOSES, Assistant Examiner. 

1. LATCHING APPARATUS FOR A DOUBLE SWINGING DOOR, A COMBINATION: A STRIKE PLATE MOUNTED ON A DOORWAY FRAME HAVING A HOLE COEXTENSIVE WITH A LATCHING RECESS IN THE FRAME, SAID STRIKE PLATE HAVING SIDE BEVELED PORTIONS APPROACHING SAID HOLE; A LATCH BOLT SLIDABLY MOUNTED WITHIN THE DOOR AND NORMALLY URGED TO AN EXTENDED POSITION AWAY FROM THE DOOR FOR SEATING IN SAID LATCHING RECESS; THE EXTENDED PORTION OF SAID BOLT CONSISTING OF A FRONT END SECTION HAVING SIDES PARALLEL TO THE PLANE OF THE DOOR DEFINING A BOLT-FACE WIDTH WHICH IS SUBSTANTIALLY LESS THAN THE WIDTH OF THE STRIKE HOLE, A REARWARD SECTION HAVING SIDES PARALLEL TO THE PLANE OF THE DOOR DEFINING A WIDTH WHICH IS ONLY SLIGHTLY LESS THAN THE WIDTH OF SAID STRIKE HOLE AND A SECTION INTERMEDIATE SAID FRONT AND REARWARD SECTIONS HAVING AT LEAST ONE TAPERED SIDE DEFINING A WIDTH THAT RANGES BETWEEN THE OTHER TWO DEFINED WIDTHS. 